Traditional Chinese medicine (TCM) practitioners here say they have seen a growing number of athletes, fitness enthusiasts and working professionals turn to the healing therapy of cupping.

This is even before many more people throughout the world came to know of the practice after American swimming champion Michael Phelps was photographed at the ongoing Rio Olympics sporting the purplish-red marks - a tell-tale sign that he has received the therapy.

Cupping is believed to relieve muscle tension by improving blood circulation, which helps to stimulate the qi, or the "vital energy" of the body.

S-League football star Jermaine Pennant has been seeking the traditional Chinese healing therapy of cupping for years, even when he was playing in England and Spain, where the practice is probably less common than in Singapore.

"I believe it brings blood and circulates (blood) to the area of the muscle that is damaged as new blood will repair it better," says the 33-year-old Tampines Rovers player, who last received the therapy two weeks ago to release the tension in his back.

According to TCM practitioners, cupping is effective for various ailments such as eczema and influenza, and muscle aches and pains, as well as for better performance.

Ms Jaime Cheong, general manager of the Singapore Athletics Association (SAA), says: "We send our athletes to TCM chain Kin Teck Tong for cupping treatment to accelerate their recovery and for better performance."

Long associated as a preferred treatment for older folks, TCM has found a younger clientele in recent years.

Kin Teck Tong reports a 95.6 per cent increase over the past two years in customers - mostly in their 30s - opting for cupping.

One such convert is national sprinter Smriti Menon, 18, who has been seeking TCM treatments such as cupping, acupuncture and massages over the past three years.

"I was a bit apprehensive about trying TCM because I hadn't heard much about it, but I trusted my coach who recommended it. The treatments help to loosen tight muscles and prevent injury," says Menon, who trains five days a week and goes for TCM treatment about once every three weeks.

A spokesman for Kin Teck Tong's Sports Hub branch says many customers ask for cupping treatment after engaging in sports and fitness activities in the vicinity.

The chain has also been providing free TCM treatments - including cupping - to selected sportsmen from SAA and the Basketball Association of Singapore in the past year.

Aegle TCM Wellness Clinique's clientele is largely made up of young working professionals in their 30s and 40s who lead active lifestyles.

One of its physicians, Ms He Dandan, says: "Mixed-martial arts fighters, marathon runners and triathletes come to our clinic to do cupping and acupuncture to help relieve sports fatigue and injury and improve performance."

At Raffles Chinese Medicine, physician Chua Hui Zi says more young professionals are going for cupping to relieve neck and back pains due to long hours sitting in front of the computer and tilting the head when using mobile phones.

Fitness instructor Rozanne Yap, 28, finds that her monthly cupping sessions, along with other TCM treatments, help to ease her muscle aches. "I experience much faster muscle recovery when I do cupping. My muscle soreness normally takes four to five days to go away. But when I do cupping, it goes away the next day," says Ms Yap, who runs fitness studio Energize Movement.

From a Western medicine perspective, cupping may help relieve pain in sore muscles with painful trigger points, says Dr Chiam Tut Fu, a consultant sports medicine physician at Pacific Healthcare. This leads to relaxation of the muscles, which improves their function and strength.

Dr Chiam adds: "An athlete with sore muscles due to hard training or injury may benefit from cupping. Otherwise, it will not be of any value."

Dr Lim Ang Tee of Changi Sports Medicine Centre says there are some studies investigating the effectiveness of cupping for relieving muscular aches and pains that appear promising. But he adds that there has yet to be large-scale quality studies published on the therapy.

Going by Phelps' haul of at least four gold medals at the ongoing Olympics - where at age 31, he is older than many other competitors - cupping may have given the champ a boost, even if it is just all in the mind.

Dr Chiam says: "There is a lot of psychological influences in sports and if the athlete feels he or she has an edge with any form of therapy, that added confidence translates to better performance."